Noonindoles A-F: Rare Indole Diterpene Amino Acid Conjugates from a Marine-Derived Fungus, Aspergillus noonimiae CMB-M0339.

Analytical scale chemical/cultivation profiling prioritized the Australian marine-derived fungus Aspergillus noonimiae CMB-M0339. Subsequent investigation permitted isolation of noonindoles A-F ( 5 - 10 ) and detection of eight minor analogues ( i - viii ) as new examples of a rare class of indole diterpene (IDT) amino acid conjugate, indicative of an acyl amino acid transferase capable of incorporating a diverse range of amino acid residues. Structures for 5 - 10 were assigned by detailed spectroscopic and X-ray crystallographic analysis. The metabolites 5-14 exhibited no antibacterial properties against G-ve and G+ve bacteria or the fungus Candida albicans , with the exception of 5 which exhibited moderate antifungal activity.